* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
ul,
ol {
  list-style: none;
}
.container {
  position: relative;
  margin: 0 auto;
  width: 300px;
  height: 300px;
  background-color: orange;
}
.container .banner {
  display: flex;
  overflow: hidden;
}
.container .banner li a {
  text-decoration: none;
}
.container .banner li a img {
  display: none;
  width: 300px;
  height: 300px;
  border-radius: 10px;
}
.container .banner li a.active img {
  display: block;
}
.container .left,
.container .right {
  position: absolute;
  top: 50%;
  width: 50px;
  height: 25px;
  text-align: center;
  line-height: 25px;
  cursor: pointer;
}
.container .left {
  left: 0;
  transform: translate(-50%, -50%);
}
.container .right {
  right: 0;
  transform: translate(50%, -50%);
}
.container .indicator {
  position: absolute;
  display: flex;
  width: 50px;
  height: 25px;
  left: 50%;
  bottom: 0;
  transform: translate(-50%);
  align-items: center;
  justify-content: center;
}
.container .indicator li {
  width: 10px;
  height: 10px;
  margin: 0 auto;
  border-radius: 50%;
  background-color: aliceblue;
}
.container .indicator li.active {
  background-color: greenyellow;
}
